While one of the rarer cancers, Grulich said gay men were 20 times more likely to develop anal cancer than any other group: “For HIV-positive men the risk is further elevated with anal cancer now the most common non AIDS-defining cancer and the third most common cancer overall for people with HIV in Australia.”

Volunteers to the study most be over 35, living in and around Sydney and have had sex with other men.

Researchers are particularly keen to hear from HIV-positive gay men.

The study involves six sessions over three years that consist of a combination of interviews and physical examinations.

“Results of the study will provide important information to guide the future introduction of anal cancer screening programs for gay men,” said Grulich.